A circular dichroism study has been undertaken on fully reduced aklylated lysozyme in a search for secondary structure in the absence of disulfide bonds, since it has never been firmly established that such structure could exist in this situation. Under a variety of conditions, 0-20 percet alpha helix (dependent upon pH), approximately 30 percent beta structure, and approximately 60 percent random coil were found. However, there was no evidence for secondary structure in 8M urea or 6M quanidine, or after peptic digestion. These results strongly support the existence of secondary structure in the absence of disulfide bonds and suggest a new approach to the study of the relationship between amino acid sequence and conformational structure. The study will be continued to examine other proteins for structure after full reduction and aklylation, and to employ degradative procedures for the purpose of identifying the smallest conformationally functional unit of the primary structure.